VLOOKUP turns a two-column range into a lookup table for matching keys to returned values in LibreOffice and Excel.

Small JavaScript library for rendering huge tables and lists by keeping only visible rows in the DOM, reducing browser load for data-heavy views.

jasmine.clock() lets tests fast-forward timers and trigger setTimeout or setInterval callbacks without waiting in real time.

Unexpected GET /__identify__ requests in Capybara test logs come from server readiness checks for Selenium-style drivers; Capybara answers them with middleware when no route exists.

Curated gem rankings help you discover active Ruby libraries by category when you need a package for a specific task.

Collect visual user feedback on web pages with one embedded button; users can capture screenshots and leave comments for designers and developers.

jQuery plugin for placeholder text in browsers without native HTML5 support, including IE6. Skips elements that already support the placeholder attribute.

Dynamically created symbols can make keyword arguments turn nil in Ruby 2.2 when a method uses several keywords and **options.

dmesg timestamps are hard to read in uptime-based form; dmesg -T converts them to human-readable date and time.

Rails file downloads need correct MIME mappings so browsers can open attachments directly instead of forcing a save dialog.

Frozen ActiveRecord instances raise can't modify frozen hash when attributes change; dup usually creates an unfrozen shallow copy, though Rails 2.3.x has a bug.

rake notes can miss TODOs in Haml, Sass, and CoffeeScript files unless Rails is taught their comment syntax and extensions.

Ruby arrays often need a fixed length when incoming data is too short or too long. A small helper can pad missing slots or truncate excess elements.

Code folding gives a quick overview of large files and reduces scrolling when working in Cucumber features or huge Ruby classes.

Use a form model or decorator with Devise by overriding resource_class in a controller, enabling sign-up-specific fields without changing the underlying user model.

Cloud services and SaaS with free tiers help developers and open source projects start without upfront cost.

Font Awesome 4 helper classes control icon size, width, lists, borders, animation, rotation, flipping, and stacked icons.

Font Awesome 4 uses structured class names to request icon variants by shape, outline, or direction. Not every tag combination exists.

Command-line access to Amazon S3 buckets on Ubuntu is easier than browser frontends; s3cmd handles uploads, downloads, sync, ACLs, and bucket administration.

rspec_candy 0.4.0 adds support for RSpec 3 and Rails 4, while dropping the unmaintained state_machine integration.

Broken image links can leave empty gaps in HTML pages. Using onerror to swap in a fallback source keeps images visible when the original file fails to load.

Image.order(created_at: :desc) sorts records descending without raw SQL and automatically qualifies column names; multiple order criteria fit in a hash.

Adjusting timestamp parts in PostgreSQL is awkward; TO_CHAR can format changed values, and TO_TIMESTAMP converts them back for further date operations.

Ruby on Rails includes parameterize for turning text into URL-friendly slugs, normalizing spaces, punctuation, and accented characters.